A wildfire burns in the mountains north of Lytton, British Columbia, Canada, during record high temperatures. Darryl Dyck / The Canadian Press via AP
A wildfire burns in the mountains north of Lytton, British Columbia, Canada, during record high temperatures. Darryl Dyck / The Canadian Press via AP
Extreme temperatures kill five million a year
Most die from the cold but the balance is expected to shift with climate change
